Keep your engine and transmission from moving under torque. These competition engineered urethane mounts are bolt-in replacements for the stock rubber mounts. You will never need to replace this mount. These mounts are also used with the T460E transmission brackets used in the 3800 engine and transmission conversions. These mounts are highly recommended when performing a 3800 engine conversion, as these will withstand more torque than the stock rubber mounts.These mounts add a little vibration to the car when the engine is at idle, but becomes unnoticeable above 1500 RPM.